<template>
  <view>
    <view>
      <my-search bgColor="#c00000" :radius="15" @click="goToSearch"></my-search>
    </view>
    <!-- 使用自定义搜索组件 -->
    <view class="scroll-view-container">
      <!-- 左侧的滚动视图区域 -->
      <scroll-view class="left-scroll-view" scroll-y :style="{height:wh + 'px'}">
        <block v-for="(item,index) in cateList" :key="index">
          <view :class="['left-scroll-view-item', index === active?'active' : '']" @click="onSeachData(index)">
            {{item.cat_name}}
          </view>
        </block>
      </scroll-view>
      <!-- 右侧的试图滚动区域 -->
      <scroll-view :scroll-top="scrollTop" class="right-scroll-view" scroll-y :style="{height:wh + 'px'}">
        <view class="right-scroll-view-item" v-for="(item2,index2) in cateLevel2" :key="index2">
          <!-- 二级列表区域 -->
          <view class="right-scroll-view-item-title">/ {{item2.cat_name}} /</view>
         <!-- 三级列表区域 -->
          <view class="cate-lv3-list">
            <view class="cate-lv3-item" v-for="(item3,index3) in item2.children" :key="index3" @click="getGoodsList(item3)">
                <image :src="item3.cat_icon" mode="widthFix"></image>
                <text>{{item3.cat_name}}</text>
            </view>
          </view>
        </view>
      </scroll-view>
    </view>
  </view>
</template>

<script>
  export default {
    data() {
      return {
        // 当前设备可用高度
        wh: 0,
        cateList: [],
        active: 0,
        cateLevel2: [],
        // 滚动条距离顶部距离
        scrollTop:0
      };
    },
    onLoad() {
      const systemInfo = uni.getSystemInfoSync()
      this.wh = systemInfo.windowHeight - 50
      this.getCateList()
    },
    methods: {
      async getCateList() {
        const {
          data: res
        } = await uni.$http.get('/api/public/v1/categories')
        if (res.meta.status !== 200) return uni.$showMsg()
        this.cateList = res.message
        // 获取二级分类
        this.cateLevel2 = res.message[0].children
      },
      onSeachData(index) {
        this.active = index
        // 切换重新为二级分类赋值
        this.cateLevel2 = this.cateList[index].children
        // 让scrollTop的值在0和1之间切换
        this.scrollTop = this.scrollTop === 0 ? 1 : 0
      },
      getGoodsList(item){
        uni.navigateTo({
          url:'/subpkg/goods_list/goods_list?cid=' + item.cat_id
        })
      },
      goToSearch(){
        uni.navigateTo({
          url:'/subpkg/search/search'
        })
      }
    }
  }
</script>

<style lang="scss">
  .scroll-view-container {
    display: flex;

    .left-scroll-view {
      width: 130px;

      .left-scroll-view-item {
        background-color: #f7f7f7;
        line-height: 60px;
        text-align: center;
        font-size: 12px;

        &.active {
          background-color: #ffffff;
          position: relative;

          &:before {
            content: '';
            display: block;
            width: 3px;
            height: 30px;
            background-color: #c00000;
            position: absolute;
            top: 50%;
            left: 0;
            transform: translateY(-50%);
          }
        }
      }
    }

    .right-scroll-view-item-title {
      text-align: center;
      font-size: 12px;
      font-weight: bold;
      padding: 15px 0;
    }
    .cate-lv3-list{
      display: flex;
      flex-wrap: wrap;
      .cate-lv3-item{
        width: 33.33%;
        display: flex;
        flex-direction: column;
        justify-content: center;
        align-items: center;
        margin-bottom: 10px;
        image{
          width: 60px;
          height: 60px;
        }
        text{
          font-size: 12px;
        }
      }
    }
  }
</style>